Question

Some adaptations, on the other hand, become useless. These adaptations are vestigial: remaining but functionless. Whales and dolphins have vestigial leg bones, the remains of an adaptation (legs) that their ancestors used to walk. Why did the author include this selection?

Answer 1

The selection on vestigial structures highlights the concept of evolution, showing how once-functional traits can become obsolete and are evidence of a common ancestry which supports the theory of evolution.

Step-by-step explanation:

The author included the selection on vestigial structures to illustrate the concept of evolution and how certain physical traits can become obsolete or nonfunctional over time. Vestigial structures like the human tailbone, whale pelvic bones, and the human appendix are examples of traits that have significantly reduced in size because they are no longer used. This reduction occurs because maintaining a full-sized, unused structure can be detrimental to an organism's fitness by wasting energy or presenting a vulnerability.

Evolutionary adaptation and natural selection tend to favor characteristics that increase an organism's ability to survive and reproduce. Therefore, over time, vestigial structures tend to shrink or disappear as there is no selective pressure to maintain them. The presence of these structures provides compelling evidence for a common ancestry among different species, reinforcing the theory of evolution.

Answer 2

This is because vestigial parts are usually homologous to most of the structures that are functional in other species of organisms. E.g.. the Vestigial legs which are non functional in whale and Dolphins, are useful to other organisms. Hence, if these organisms possessed these structures, they should share certain characteristics with each other.Therefore these organisms can be said to evolved from one another.Thus their vestigial organism should be included by the author as evidence of evolution.

Step-by-step explanation: